Tsugaruite is a rare lead-arsenic sulfosalt primarily known from the Yunosawa mine in Japan. It typically forms thin, white to pale yellow tabular crystals and is highly valued by specialized collectors of sulfosalt minerals.
Is this tsugaruite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch tsugaruite with a known reference. Tsugaruite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: lead gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: silvery lead gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular.
Often confused with
Tsugaruite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside tsugaruite
Minerals reported to co-occur with tsugaruite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂₈As₁₅S₅₀Cl
- Mohs hardness
- 2.5-3
- Density
- 6.12 g/cm³
- Colors
- Silvery lead gray
- Streak
- Lead gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Found in a veinlet of barite at the Yunosawa mine
Where rockhounds find tsugaruite
Classic worldwide localities
- Minami-Tsugara-gun provincial unit of the Aomori Prefecture in northern Japan (type locality)
Field-hunting tip
Where it forms: Found in a veinlet of barite at the Yunosawa mine. If you start seeing galena, sphalerite, pyrite in float, you are in the right ground. Typical habit: tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tsugaruite?+
Where is tsugaruite found?+
Is tsugaruite safe to handle?+
What rocks look like tsugaruite?+
What minerals are found with tsugaruite?+
What kind of rock does tsugaruite form in?+
What is tsugaruite used for?+
Find tsugaruite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
